By Patricia Murphy

CQ-Roll Call

We all know Washington is about relationships. I’ve gotten some of my best scoops (so to speak) at the dog park and met some of my best sources on “Wing Night” at the Capitol Lounge years ago. On Capitol Hill, good bills have died over years-long grudges, while mediocre bills have gotten by on “Well, I just like the guy (or lady).”

With a huge legislative agenda to pass and a major international incident looming in North Korea, you’d think that President Donald Trump would be rallying his fellow Republicans to his side, especially the most senior leaders who could shepherd his agenda through the Hill. Instead, he has attacked, lied about, demeaned, ignored or otherwise alienated a host of GOP senators, including the ones crucial to his efforts to build a wall, pass tax reform, reform health care and, if it came to it, escape impeachment.

He can be the president alone, but he can’t be a successful president alone.

So let’s take a look under the hood of President Trump’s efforts so far to win friends and influence people in Washington, specifically the Republicans who chair Senate committees.

Foreign Relations Chairman Bob Corker — As chairman, Corker oversees the State Department and the nominations of all of the president’s ambassadors. He would typically be a partner in the president’s foreign policy and, if necessary, would be the one to shepherd through Congress any attempt by the president to declare war on another country.

Since the weekend, the president has mocked Corker as “Liddle Bob” on Twitter and claimed the Tennessee senator “begged” him for his endorsement, which he refused. Corker has denied this. Trump also blamed Corker for the Iran deal, which Corker opposed, and called Corker a “negative voice” trying to stop the president’s “great agenda.”

To put a bow on the relationship, which in normal times would be strong, Corker tweeted that the White House has become “an adult day care center.”

Sen. John McCain — At the top of the Senate Armed Services Committee, McCain oversees the Pentagon, force deployments and military procurement. If the president wants to send troops into harm’s way, it’s McCain who would support or kill that decision.

Since the earliest days of his campaign, Trump has had a deep, unrelenting problem with the senator from Arizona. He said McCain was “not a war hero” at a candidate forum and mocked him as a “dummy” on Twitter.

As president, Trump has lashed out at McCain for voting ‘no’ on the Obamacare repeal effort and reportedly imitated a stiff-shouldered thumbs-down to a conservative group visiting the Oval Office, apparently in reference to McCain’s arm injuries that he sustained as a prisoner of war, a joke McCain’s daughter called “abhorrent.”

Judiciary Chairman Chuck Grassley — Not only does Grassley chair the committee that needs to greenlight all of Trump’s Supreme Court and judicial nominations, he oversees the Justice Department, the FBI and, in theory, should be at the center of any discussion on immigration reform.

As Trump began his term, Grassley tweeted at him again and again, once to “Whoever at WH monitors Twitter for businessman president Trump” — ostensibly to get the president’s attention on everything from White House tours to document disclosures.

When the Judiciary Committee moved forward with its Russia investigation over the summer, the president tweeted about the committee’s “phony Russian Witch Hunt” and wrote about Grassley, “It’s very sad that Republicans, even some that were carried over the line on my back, do very little to protect their President.”

When news broke in September that the president had struck a deal with Democratic leaders on the so-called Dreamers, Grassley’s only recourse was to Tweet back at Trump. “@realDonaldTrump Morn news says u made deal w Schumer on DACA/hv ur staff brief me/ I know u undercut JudiCimm effort 4 biparty agreement.”

The list goes on. After Sen. Lisa Murkowski, the chairwoman of the Energy and Natural Resources Committee, voted against the Obamacare repeal, Interior Secretary Ryan Zinke called to threaten future projects in her state, projects that she technically controls as head of the committee.

When Sen. Richard Burr, chairman of the Intelligence Committee, held a hearing on possible connections between the Trump administration and Russia, the president tweeted, “Why Isn’t the Senate Intel Committee looking into the Fake News Networks in OUR country to see why so much of our news is just made up-FAKE!”

Along with Steve Bannon’s threats to primary nearly a dozen sitting Republican senators and Trump’s ongoing feud with Senate Majority Leader Mitch McConnell, the rest of us can come to one of two conclusions — either the president doesn’t know how crucial Congress is to his agenda, or he doesn’t care one way or another if his agenda passes.

It’s certainly easier to blame a failure on legislators few people have heard of than to actually do the hard work of passing an agenda. It seems like the president has decided which route he’s going to take.

Roll Call columnist Patricia Murphy covers national politics for The Daily Beast. Previously, she was the Capitol Hill bureau chief for Politics Daily and founder and editor of Citizen Jane Politics.